Rear-projection screens are utilized for various applications, such as, for example, advertising in store windows, show rooms, exhibitions, shopping malls, lobbies, restaurants, museums and various transportation stations. In such applications, an image source located behind the screen projects image light forward along a projection axis toward the screen to form a visible image at the plane of the screen which is distributed to viewers on both the receiving or rear side of the screen and the opposing, front side of the screen. Typical screen characteristics used to describe a screen's performance include contrast, image brightness, visible light transmittance, visible light absorbance and visible light reflectance.
It is generally desirable to have a rear-projection screen where the image is visible on both the front and rear surfaces and that has high image contrast and high image brightness in daylight and at night. Unfortunately, as one screen characteristic is improved, one or more other screen characteristics often degrade. For example, image contrast can be somewhat improved by incorporating a light-absorbing materials and/or light-diffusing elements in the screen for redirecting the ambient light. Often when the reflected ambient light is reduced by this technique, image brightness on one or both surfaces is also reduced because the screen has become more opaque. As a result, there is little or no effective gain in the image quality. For this reason, certain tradeoffs are made in screen characteristics and performance in order to produce a screen that has acceptable overall performance for the particular rear-projection display application. Display applications intended to be viewable on a window from both the interior and exterior of a building are particularly challenging to manufacturers since that the relative amount of sunlight reflected from the window is much greater than the ambient light reflected inside of the building.